package demo;

/**
 *  二叉树的最近公共祖先
 */
class Solution16 {
	public TreeNode lowestCommonAncestor(TreeNode root, TreeNode p, TreeNode q) {
		if (root == null || p == root || q == root) {
			return root;
		}
		TreeNode left = lowestCommonAncestor(root.left, p, q);
		TreeNode right = lowestCommonAncestor(root.right, p, q);
		if (left != null && right != null) {
			return root;
		}
		if (left == null && right == null) {
			return null;
		}
		return left == null ? right : left;
	}
}

